Chemical treatment apparatus for diluting and activating polymers and methods thereof

ABSTRACT

A chemical treatment apparatus for diluting and activating a polymeric material can include a mixing chamber having a first end, a second end, a first baffle plate positioned between the first end and second end, a high shear mixing zone positioned between the first end of the mixing chamber and the first baffle plate, and a low shear mixing zone positioned downstream from the high shear agitation zone between the second end of the mixing chamber and the first baffle plate. The volume ratio of the high shear mixing zone to the low shear mixing zone can be in the range of 1:2 to 1:10. A method and system for diluting and activating polymeric materials are also disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/863,839, filed Sep. 24, 2015, entitled “Chemical Treatment Apparatusfor Diluting and Activating Polymers and Methods Thereof”, which claimspriority to U.S. Provisional Application No. 62/055,839 filed Sep. 26,2014, which are both incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a chemical treatment apparatus fordiluting and activating polymeric materials as well as methods ofdiluting and activating polymeric materials using the chemical treatmentapparatus.

Description of Related Art

Polymeric materials such as polyelectrolytes are often used asflocculants and coagulants for treating wastewater. These polymericmaterials typically have a long-chain structure with a high-molecularweight and are tightly tangled prior to activation. To untangle andactivate these materials for use, such as for treating wastewater, thepolymeric materials are diluted and mixed with water. The degree ofactivation can be determined by measuring the viscosity of the resultingpolymeric solutions. Generally, viscosity increases as the polymer isuntangled and becomes more activated with a minimum degree of damage tothe long-chain structure. The maximum viscosity associated with a fullyactivated polymer will vary based on the chemical structure of thepolymeric material.

Typically, when a high-molecular weight polymeric material contactswater, a sticky layer forms around the outer surface resulting in theformation of aggregates or “fisheyes”. These fisheyes make it difficultfor water to penetrate and hydrate the tangled polymeric material,thereby increasing the time needed to completely activate the tangledpolymeric material. To prevent the formation of fisheyes, high shearagitation is used to mix the polymeric material with water. As waterbegins to hydrate the polymeric material during this mixing step, thelong-chain structure of the polymer starts to untangle. The molecules ofthe partially-hydrated polymeric material are very fragile and areeasily damaged by the energy created by the high shear agitation. Due tothe increased fragility of the polymer molecules, low shear agitation issometimes used in lieu of or in addition to high shear agitation. Whilelow shear agitation is less damaging, this mixing technique increasesthe period of time it takes to activate the polymeric materials.

Extensive time and efforts have been expended in developing apparatusesand methods for diluting and activating polymeric materials. While theseapparatuses and methods have overcome some of the drawbacks associatedwith the prior art, there is still a need for an improved apparatus andmethod that can quickly and efficiently dilute and activate polymericmaterials.

SUMMARY OF THE INVENTION

Accordingly, and generally, provided is an improved chemical treatmentapparatus and method for diluting and activating a polymeric material.

The present invention is directed to a chemical treatment apparatus fordiluting and activating a polymeric material. The apparatus can includea mixing chamber having a first end, a second end, a first baffle platepositioned between the first end and second end, a high shear mixingzone positioned between the first end of the mixing chamber and thefirst baffle plate, and a low shear mixing zone positioned downstreamfrom the high shear mixing zone between the second end of the mixingchamber and the first baffle plate. The volume ratio of the high shearmixing zone to the low shear mixing zone can be from 1:2 to 1:10. Thechemical treatment apparatus can also include a mechanical mixing deviceand a static mixer. The mechanical mixing device can be connected to thefirst end of the mixing chamber and extend into the high shear mixingzone, and the static mixer can be positioned at the second end of themixing chamber. In some aspects, the low shear mixing zone can becompletely free of a mechanical mixing device.

Further, the mechanical mixing device can include a motor and animpeller. The impeller can be positioned within the high shear mixingzone. The motor can be directly connected to the impeller.

As indicated, the chemical treatment apparatus can include a firstbaffle plate. To allow fluid to flow from the high shear mixing zone andinto the low shear mixing zone, the first baffle plate can include aplurality of pathways. In some aspects, the chemical treatment apparatuscan include a second baffle plate positioned between the first baffleplate and the second end of the mixing chamber.

In addition, the volume of the mixing chamber can be greater than orequal to a half gallon, and the length of the static mixer can begreater than 5 inches. A post-dilution zone can also be positionedbetween the second end of the mixing chamber and the static mixer.

The present invention further includes a method of diluting andactivating a polymeric material. The method can include: transporting apolymeric material and water into a mixing chamber having a first end, asecond end, a first baffle plate positioned between the first end andsecond end, a high shear mixing zone positioned between the first end ofthe mixing chamber and the first baffle plate, and a low shear mixingzone positioned downstream from the high shear mixing zone between thesecond end of the mixing chamber and the first baffle plate; and mixingthe polymeric material and water in the high shear mixing zone with amechanical mixing device. The volume ratio of the high shear mixing zoneto the low shear mixing zone can be from 1:2 to 1:10, and the low shearmixing zone can be completely free of a mechanical mixing device.

The method can further include post-diluting the mixed polymericmaterial and water in a post-dilution zone, and mixing the post-dilutedmixture of polymeric material and water in a static mixer. Thepost-diluted mixture can have a polymeric material concentration of0.25% to 1%.

Further, the mechanical mixing device can include a motor and animpeller. The impeller can be positioned within the high shear mixingzone. The motor can be directly connected to the impeller.

As indicated, the chemical treatment apparatus can include a firstbaffle plate. To allow fluid to flow from the high shear mixing zone andinto the low shear mixing zone, the first baffle plate can include aplurality of pathways. In some aspects, the chemical treatment apparatuscan include a second baffle plate positioned between the first baffleplate and the second end of the mixing chamber.

In addition, the volume of the mixing chamber can be greater than orequal to a half gallon, and the length of the static mixer can begreater than 5 inches. A post-dilution zone can also be positionedbetween the second end of the mixing chamber and the static mixer.

The present invention further includes a system for diluting andactivating a polymeric material. The system can include a chemicaltreatment apparatus that includes: a mixing chamber having a first end,a second end, a first baffle plate positioned between the first end andsecond end, a high shear mixing zone positioned between the first end ofthe mixing chamber and the first baffle plate, and a low shear mixingzone positioned downstream from the high shear mixing zone between thesecond end of the mixing chamber and the first baffle plate; amechanical mixing device connected to the first end of the mixingchamber and extending into the high shear mixing zone; and a staticmixer positioned at the second end of the mixing chamber. The volumeratio of the high shear mixing zone to the low shear mixing zone can befrom 1:2 to 1:10, and the low shear mixing zone is completely free of amechanical mixing device.

The system also includes a water distribution apparatus in fluidcommunication with the chemical treatment apparatus as well as a polymerdistribution apparatus in fluid communication with the chemicaltreatment apparatus. In certain aspects, the chemical treatmentapparatus, water distribution apparatus, and/or polymer distributionapparatus are operated with a controller.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a chemical treatment apparatusaccording to the principles of the present invention;

FIG. 2 is a cross-sectional view of a mixing chamber according to theprinciples of the present invention;

FIG. 3 is a cross-sectional view of the mixing chamber of FIG. 2attached to a motor;

FIG. 4 is a cross-sectional view of a system for diluting and activatingpolymeric materials according to the principles of the presentinvention;

FIG. 5 is a perspective view of a chemical treatment apparatus accordingto the principles of the present invention; and

FIG. 6 is a perspective view of a portion of the chemical treatmentapparatus of FIG. 5 in fluid communication with a water distributionapparatus.

DESCRIPTION OF THE INVENTION

For purposes of the following detailed description, it is to beunderstood that the invention may assume various alternative variationsand step sequences, except where expressly specified to the contrary.Moreover, other than in any operating examples, or where otherwiseindicated, all numbers expressing, for example, quantities ofingredients used in the specification and claims are to be understood asbeing modified in all instances by the term “about”. Accordingly, unlessindicated to the contrary, the numerical parameters set forth in thefollowing specification and attached claims are approximations that mayvary depending upon the desired properties to be obtained by the presentinvention. At the very least, and not as an attempt to limit theapplication of the doctrine of equivalents to the scope of the claims,each numerical parameter should at least be construed in light of thenumber of reported significant digits and by applying ordinary roundingtechniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard variation found in theirrespective testing measurements.

Also, it should be understood that any numerical range recited herein isintended to include all sub-ranges subsumed therein. For example, arange of “1 to 10” is intended to include all sub-ranges between (andincluding) the recited minimum value of 1 and the recited maximum valueof 10, that is, having a minimum value equal to or greater than 1 and amaximum value of equal to or less than 10.

Further, the terms “upper,” “lower,” “right,” “left,” “vertical,”“horizontal,” “top,” “bottom,” “lateral,” “longitudinal,” andderivatives thereof shall relate to the invention as it is oriented inthe drawing figures. However, it is to be understood that the inventionmay assume alternative variations and step sequences, except whereexpressly specified to the contrary. It is also to be understood thatthe specific devices and processes illustrated in the attached drawings,and described in the specification, are simply exemplary embodiments andaspects of the invention. Hence, specific dimensions and other physicalcharacteristics related to the embodiments and aspects disclosed hereinare not to be considered as limiting.

In this application, the use of the singular includes the plural andplural encompasses singular, unless specifically stated otherwise. Inaddition, in this application, the use of “or” means “and/or” unlessspecifically stated otherwise, even though “and/or” may be explicitlyused in certain instances.

The present invention is directed to a chemical treatment apparatus 10for diluting and activating polymeric materials. As used herein,“polymeric materials” refers to materials that include a polymer. A“polymer” means homopolymers (e.g., prepared from a single monomerspecies), copolymers (e.g., prepared from at least two monomer species),and graft polymers. The polymeric materials can have various formsincluding, but not limited to, polymer beads, powders, water in oilemulsions, concentrated solution gels, and combinations thereof.

As shown in FIG. 1, and in one non-limiting embodiment or aspect, thechemical treatment apparatus 10 can include a mixing chamber 12 having afirst end 14, a second end 16, and a first baffle plate 18 positionedbetween the first end 14 and the second end 16. A high shear mixing zone20 can be positioned between the first end 14 of the mixing chamber 12and the first baffle plate 18. A low shear mixing zone 22 can bepositioned downstream from the high shear mixing zone 20 between thesecond end 16 of the mixing chamber 12 and the first baffle plate 18. Asused herein, “downstream” refers to the direction of the flow of workingfluid. As such, the low shear mixing zone 22 “downstream” from the highshear mixing zone 20 means that working fluid will flow from the highshear mixing zone 20 and into the low shear mixing zone 22 duringoperation of the chemical treatment apparatus 10. As shown in FIG. 1,the first baffle plate 18 can have a plurality of pathways 19 thatallows fluid to flow from the high shear mixing zone 20 and into the lowshear mixing zone 22 during operation of the chemical treatmentapparatus 10. The first baffle plate 18 can have a diameter that isequal to the internal diameter of the mixing chamber 12.

As used herein, “high shear” refers to agitation that produces a shearrate above 4,500 sec.⁻¹, and “low shear” refers to agitation thatproduces a shear rate below 4,500 sec.⁻¹. “Shear rate” is the rate atwhich progressive shearing deformation is applied to a material. Shearrate can be determined using the G value or mean shear rate, which maybe characterized for a Newtonian fluid such as water in accordance withequation (I) below:

$\begin{matrix}{G = {\left( \frac{P}{\mu\; V} \right)^{1/2}.}} & (I)\end{matrix}$With reference to equation (I), P is the power dissipated by the fluidmotion, μ is the fluid dynamic viscosity, and V is the fluid volume inthe mixing vessel. The determination of shear rate is also disclosed inU.S. Pat. No. 5,164,429 at column 4, lines 11 to 47, the relevantportions of which are incorporated by reference herein.

Further, the total volume of the mixing chamber 12 can be greater thanor equal to a half gallon, such as greater than or equal to one gallon.The volume of the low shear mixing zone 22 can also be larger than thevolume of the high shear mixing zone 20. For example, the volume ratioof the high shear mixing zone to the low shear mixing zone is in therange of 1:2 to 1:10. In some aspects, the volume ratio of the highshear mixing zone to the low shear mixing zone is in the range of 1:2 to1:8, such as from 1:2 to 1:6, such as from 1:2 to 1:4. The volume ratiosdescribed herein sufficiently dilute and activate polymeric materialswithin a reasonable time period without damaging or affecting theproperties of the polymers.

Referring to FIG. 1, the chemical treatment apparatus 10 can furtherinclude a mechanical mixing device 24. The mechanical mixing device 24can be connected to the first end 14 of the mixing chamber 12 and extendinto the high shear mixing zone 20. As used herein, a “mechanical mixingdevice” refers to a device or apparatus that can blend, disperse, and/orcombine various materials using energy provided by movement ofmechanical parts or components. For example, the mechanical mixingdevice 24 can include a motor 28 and mechanical parts or components thatmove with the use of the motor 28. In some aspects; the mechanicalmixing device 24 includes an impeller or mixing rotor 26 and a motor 28.As shown in FIG. 1, the impeller or mixing rotor 26 can be positionedwithin the high shear mixing zone 20 and connect to the motor 28 at thefirst end 14 of the mixing chamber 12. The impeller or mixing rotor 26can be directly connected to the motor 28. As used herein, “directlyconnected” means that the impeller or mixing rotor 26 is connected tothe motor 28 without the use of a coupler or other intermediaryconnecting device. For example, FIG. 2 depicts a mixing chamber 12 thatcomprises an impeller 26 positioned within the high shear mixing zone20. As shown in FIG. 2, a shaft 27 from the impeller 26 can extend outfrom the first end 14 of the mixing chamber 12. Referring to FIG. 3, amotor 28 can then be directly connected to the shaft 27 of the impeller26. As further shown in FIG. 3, the motor 28 can be secured to themixing chamber 12 with a mounting device 29 such as a bracket. Bydirectly connecting the impeller 26 to the motor 28, the size of thechemical treatment apparatus 10 can be decreased and/or the size ofother components such as the mixing chamber 12 and static mixer 34 canbe increased without increasing the overall size of chemical treatmentapparatuses currently being used. This allows for easy replacement ofconventional chemical treatment apparatuses for the chemical treatmentapparatus 10 of the invention described herein.

As explained above, shear rate can be determined using the G value ormean shear rate. When the fluid motion in the high shear mixing zone 20is created by an impeller 26, P (power dissipated by the fluid motion)can be calculated using equation (II) below:P=2πNT   (II).With reference to equation (II), N is the rotational speed of theimpeller 26 and T is the measured torque. In such cases, the G value canbe calculated in accordance with equation (III), as follows:

$\begin{matrix}{G = {\left( \frac{2\pi\;{NT}}{\mu\; V} \right)^{1/2}.}} & ({III})\end{matrix}$

As seen in equation (III), mean shear rate G may be determinedexperimentally by measuring actual power transmission to the fluid, thatis, by measuring the rotational speed of the impeller 26, the torque ofthe impeller 26, the viscosity of the fluid, and the fluid volume in thehigh shear mixing zone 20.

Referring again to FIG. 1, the low shear mixing zone 22 does not contain(i.e., is completely free of) a mechanical mixing device 24. As such,the low shear mixing zone 22 can be completely free of an impeller ormixing rotor 26. This ensures that the polymeric materials are subjectedto shear rates below 4,500 sec.⁻¹ in the low shear mixing zone 22.

As shown in FIGS. 1-3, the mixing chamber 12 can also include a secondbaffle plate 30. The second baffle plate 30 can be positioned betweenthe first baffle plate 18 and the second end 16 of the mixing chamber12. The second baffle plate 30 can have a diameter that is less than thediameter of the first baffle plate 18. Further, the second baffle plate30 can be used to adjust the flow of fluid within the low shear mixingzone 22. For instance, fluid can flow from the high shear mixing zone20, through the plurality of pathways 19 in the first baffle plate 18,and into the low shear mixing zone 22 where the fluid will flow into thesecond baffle plate 30, thereby causing the fluid to be diverted in adifferent direction to flow around the second baffle plate 30. Thus, asshown in FIGS. 1-3, the pathways 19 can be aligned in the first baffleplate 18 such that fluid is directed into the second baffle plate 30. Byadjusting the flow of fluid within the low shear mixing zone 22, thesecond baffle plate 30 can induce a turbulent flow to cause furthermixing of water and the polymeric materials in the low shear mixing zone22 at a low shear rate.

As shown in FIGS. 1-3, the mixing chamber 12 can include a primary waterpassageway 23, such as a pipe, that extends from the second end 16 ofthe mixing chamber 12, through the low shear mixing zone 22, and intothe high shear zone 20 such that water is delivered directly into thehigh shear mixing zone 20. Water entering the high shear mixing zone 20through the primary water passageway 23 can then be mixed with apolymeric material. The polymeric material can enter the high shearmixing zone 20 from the first end 14 of the mixing chamber 12.

Referring to FIG. 1, the chemical treatment apparatus 10 can include apost-dilution zone 32. The post-dilution zone 32 can be positioned nearor adjacent to the second end 16 of the mixing chamber 12 such that thediluted and activated polymeric materials exiting the mixing chamber 12can be further diluted with water in the post-dilution zone 32. Waterfor the post-dilution process can be delivered into the chemicaltreatment apparatus 10 through a post-dilution water entry or port 33located near or adjacent to the second end 16 of the mixing chamber 12.Post-dilution water can then flow to the post-dilution zone 32 where itmixes with the diluted and activated polymeric materials exiting themixing chamber 12. In certain aspects, post-dilution water flows intothe diluted and activated polymeric materials exiting the mixing chamber12 at a direction perpendicular to the flow of the diluted and activatedpolymeric materials.

The post-dilution zone 32 can be used to reduce the polymerconcentration. For example, the polymeric materials can be diluted inthe mixing chamber 12 to obtain a first concentration, such as a 1%concentration. After exiting the mixing chamber 12, the polymericmaterials can be diluted further in the post-dilution zone 32 to asecond polymer concentration, such as in the range of 0.25% to 0.5%. Assuch, the chemical treatment apparatus 10 can be used to obtainactivated polymers at concentrations of 0.25% to 1%.

Referring again to FIG. 1, the chemical treatment apparatus 10 can alsoinclude a static mixer 34. The static mixer 34 can be connected to thepost-dilution zone 32 to mix the post-diluted polymeric materials. Asindicated above, by directly connecting the impeller or mixing rotor 26to the motor 28, the size of the static mixer 34 can be increased ascompared to other static mixers 34 used with conventional chemicaltreatment apparatuses. The length of the static mixer 34 can be greaterthan 5 inches or greater than 5.5 inches or greater than 6 inches. Theextended static mixer 34 can mix the post-diluted polymeric materials toform a homogenous mixture of activated polymers.

After mixing, the diluted and activated polymeric materials can exit thechemical treatment apparatus 10 through a fluid outlet 40. For example,as shown in FIG. 1, the fluid outlet 40 can be connected to the staticmixer 34 where the post-diluted and activated polymeric materials canexit the chemical treatment apparatus 10.

As indicated above, the present invention is also directed to a methodof diluting and activating polymeric materials. In a non-limitingembodiment or aspect, the method includes transporting a polymericmaterial and water into a mixing chamber 12 of a chemical treatmentapparatus 10. The mixing chamber 12 can include, but is not limited to,any of the aspects of the invention described above. For example, asshown in FIG. 1, the method of diluting and activating a polymericmaterial includes transporting polymeric materials and water into amixing chamber 12 having a first end 14, a second end 16, a first baffleplate 18 positioned between the first end 14 and the second end 16, ahigh shear mixing zone 20 positioned between the first end 14 of themixing chamber 12 and the first baffle plate 18, and a low shear mixingzone 22 positioned downstream from the high shear mixing zone 20 betweenthe second end 16 of the mixing chamber 12 and the first baffle plate18. The method can include transporting a polymeric material and waterto the high shear mixing zone 20 and mixing the polymeric material andwater in the high shear mixing zone 20 with a mechanical mixing device24 as described above. As shown in FIGS. 1-3, water can be delivereddirectly into the high shear mixing zone 20 such as through the primarywater passageway 23.

After mixing the polymeric material with water in the high shear mixingzone 20, the mixture can flow into the low shear mixing zone 22, such asthrough a plurality of pathways 19 located in the first baffle plate 18.The method can then include mixing the polymeric material and water at alow shear rate in the low shear mixing zone 22. In certain aspects, thelow shear mixing zone 22 is completely free of a mechanical mixingdevice 24 (such as an impeller 26 and/or motor 28). The mixing chamber12 can also include a second baffle plate 30 positioned between thefirst baffle plate 18 and the second end 16 of the mixing chamber 12. Aspreviously described, the second baffle plate 30 can be used to adjustthe flow of fluid within the low shear mixing zone 22 and induce aturbulent flow to cause further mixing of water and the polymericmaterial in the low shear mixing zone 22. Thus, the method of dilutingand activating polymeric materials can include inducing a turbulent flowwithin the low shear mixing zone 22 of the mixing chamber 12.

Further, and as described above, the volume of the low shear mixing zone22 of the mixing chamber 12 can be larger than the volume of the highshear mixing zone 20. For instance, the volume ratio of the high shearmixing zone 20 to the low shear mixing zone 22 can be in the range of1:2 to 1:10, such as from 1:2 to 1:8, such as from 1:2 to 1:6. As aresult, the low shear mixing time can be longer than the high shearmixing time. By using a longer low shear mixing time, the polymericmaterials can be diluted and activated within a reasonable time withoutdamaging or effecting the properties of the polymer.

The method can further include post-diluting the diluted/activatedpolymeric materials in a post-dilution zone 32, and mixing thepost-diluted polymeric materials in a static mixer 34. As indicatedabove, the size of the static mixer 34 can be increased as compared tocurrent conventional apparatuses for diluting and activating polymericmaterials. The post-dilution zone 32 and extended static mixer 34 can beused with the present method to further dilute and form a homogenousmixture after mixing the materials in the mixing chamber 12.

In addition to the above, the present invention is also directed to asystem for diluting and activating polymeric materials. Referring toFIG. 4, the system includes a chemical treatment apparatus 10, a waterdistribution apparatus 50 in fluid communication with the chemicaltreatment apparatus 10, and a polymer distribution apparatus 60 in fluidcommunication with the chemical treatment apparatus 10. The chemicaltreatment apparatus 10 can include any of the aspects of the inventiondescribed in detail above. The water distribution apparatus 50 caninclude a series of pipes, valves, and pumps that are connected to awater source and which can be controlled to transport water to thechemical treatment apparatus 10. The water distribution apparatus 50 caninclude a primary water distribution line 52 for providing water to themixing chamber 12 and a post-dilution water line 54 for providing waterto the post-dilution zone 32. As shown in FIG. 4, the primary waterdistribution line 52 and the post-dilution water line 54 can beconnected to the second end 16 of the mixing chamber 12, such as to theprimary water passageway 23, and/or the port 33 that leads to thepost-dilution zone 32. FIG. 5 further illustrates the post-dilutionwater entry/port 33 and primary water passageway 23 of a chemicaltreatment apparatus 10 that is not in fluid communication with a waterdistribution apparatus 50. FIG. 6 illustrates the post-dilution waterentry/port 33 and primary water passageway 23 of a chemical treatmentapparatus 10 that is in fluid communication with a water distributionapparatus 50 through the primary water distribution line 52 and thepost-dilution water line 54.

Referring to FIG. 4, the polymer distribution apparatus 60 can alsoinclude a series of pipes, valves, and pumps that are connected to apolymer storage source and which can be controlled to transport polymersto the chemical treatment apparatus 10. In addition, the polymerdistribution apparatus 60 can include a polymer distribution line. Asshown in FIG. 4, the polymer distribution line can deliver polymericmaterials to the first end 14 of the mixing chamber 12 where they canenter the high shear mixing zone 20.

As further shown in FIG. 4, the chemical treatment apparatus 10, waterdistribution apparatus 50, and/or polymer distribution apparatus 60 canbe operated automatically with a controller 70 such as, for example, aprogrammable logic controller, a microprocessor, a central processingunit, and/or any other like device capable of processing data, such as acomputing device having programmable instructions or software thereon,which, when executed by a processor of the computing device, cause theprocessor to implement or facilitate the described steps.

The following examples are presented to demonstrate the generalprinciples of the invention. The invention should not be considered aslimited to the specific examples presented. All parts and percentages inthe examples are by weight unless otherwise indicated.

EXAMPLE 1 Polymer Dilution and Activation

ZETAG® 7878 (copolymer of acrylamide and a quaternized cationic monomer,commercially available from BASF) and ALCOMER® 120L (copolymer ofacrylamide and acrylic acid, commercially available from BASF) weremixed with water in a chemical treatment apparatus that includes amixing chamber with an inside diameter of about 5.5 inches, a length ofabout 8.6 inches, and a volume of about 0.9 gallons. The mixing chamberincluded a first baffle plate, a high shear mixing zone, and a low shearmixing zone. The volume ratio of the high shear mixing zone to the lowshear mixing zone was approximately 1:2.2. Further, a second baffleplate was positioned in the low shear mixing zone and a rotatingimpeller was positioned in the high shear mixing zone. A motor wasdirectly connected to the impeller and mounted to the first end of themixing chamber with a bracket. The chemical treatment apparatus alsoincluded a post-dilution zone and a static mixer with a length of about6.5 inches.

The chemical treatment apparatus was operated with a microcontroller toprepare polymeric solutions of ZETAG® and ALCOMER® 120L at aconcentration of 0.5%. Throughout the process, the polymeric solutionswere kept at a temperature of 73° F. to 74° F., the water flow rate intothe mixing chamber was 300 gallons per hour (gph)+/−10 gph, and theimpeller was run at 3,450 revolutions per minute (rpm). The polymericsolutions were aged for a period of time ranging from 1 minute to 60minutes.

EXAMPLE 2 Polymer Dilution and Activation

ZETAG® 7878 (copolymer of acrylamide and a quaternized cationic monomer,commercially available from BASF) and ALCOMER® 120L (copolymer ofacrylamide and acrylic acid, commercially available from BASF) weremixed with water in a chemical treatment apparatus that includes amixing chamber with an inside diameter of about 5.5 inches, a length ofabout 5.0 inches, and a volume of about 0.5 gallons. The mixing chamberhad a first baffle plate, a high shear mixing zone, and a low shearmixing zone. The volume ratio of the high shear mixing zone to the lowshear mixing zone was approximately 1:0.8. Further, a second baffleplate was positioned in the low shear mixing zone and a rotatingimpeller was positioned in the high shear mixing zone. A motor wasindirectly connected to the impeller with the use of a coupler. Thechemical treatment apparatus also included a post-dilution zone and astatic mixer with a length of about 4.8 inches.

The chemical treatment apparatus was operated with a microcontroller toprepare polymeric solutions of ZETAG® 7878 and ALCOMER® 120L at aconcentration of 0.5%. Throughout the process, the polymeric solutionswere kept at a temperature of 73° F. to 74° F., the water flow rate intothe mixing chamber was 300 gallons per hour (gph)+/−10 gph, and theimpeller was run at 3,450 revolutions per minute (rpm). The polymericsolutions were aged for a period of time ranging from 1 minute to 60minutes.

EXAMPLE 3 Viscosity Evaluation

The viscosities of the polymeric solutions prepared in Examples 1 and 2were determined using a Brookfield LV spindle 2, 6 rpm (max range 5,000centipoise (cp)) viscometer. The viscosities of the Zetag® 7878 andAlcomer® 120L polymeric solutions are shown in Tables 1 and 2,respectively.

TABLE 1 Viscosity Data for ZETAG ® 7878 Polymeric Solutions Viscosity(cp) Viscosity (cp) Percent Aging Time of Example 1 of Example 2Viscosity (min.)¹ Solutions ² Solutions ³ Change (%) ⁴ 1 395 372 6.2 151140 1080 5.6 30 1340 1220 9.8 60 1525 1330 14.7 ¹Aging time of ZETAG ®7878 solutions after mixing. ² Viscosity of ZETAG ® 7878 polymericsolutions prepared using the apparatus of Example 1. ³ Viscosity ofZETAG ® 7878 polymeric solutions prepared using the apparatus of Example2. ⁴ Percent change in viscosity between the polymeric solutionsprepared using the apparatus of Example 1 and the polymeric solutionsprepared using the apparatus of Example 2.

TABLE 2 Viscosity Data for ALCOMER ® 120L Polymer Solutions Viscosity(cp) Viscosity (cp) Percent Aging Time of Example 1 of Example 2Viscosity (min.)¹ Solutions ² Solutions ³ Change (%) ⁴ 1 1905 1795 6.115 2310 2185 5.7 30 2505 2385 5.0 60 2615 2520 3.8 ¹Aging time ofALCOMER ® 120L solutions after mixing. ² Viscosity of ALCOMER ® 120Lpolymeric solutions prepared using the apparatus of Example 1. ³Viscosity of ALCOMER ® 120L polymeric solutions prepared using theapparatus of Example 2. ⁴ Percent change in viscosity between thepolymeric solutions prepared using the apparatus of Example 1 and thepolymeric solutions prepared using the apparatus of Example 2.

As shown in Tables 1 and 2, polymeric solutions prepared using theapparatus of Example 1 had higher viscosities than the polymericsolutions prepared using the apparatus of Example 2. Particularly,polymeric solutions prepared using the apparatus of Example 1 had anaverage viscosity increase of between 5% and 10% when compared to thepolymeric solutions prepared using the apparatus of Example 2. Thus, theviscosity data shown in Tables 1 and 2 demonstrate that an extendedmixing chamber having a larger low shear mixing zone, according to someaspects of the present invention, can be used to produce a more fullyactivated polymer.

Further non-limiting embodiments or aspects are set forth in thefollowing clauses.

Clause 1: A chemical treatment apparatus for diluting and activating apolymeric material comprising: a mixing chamber comprising a first end,a second end, a first baffle plate positioned between the first end andsecond end, a high shear mixing zone positioned between the first end ofthe mixing chamber and the first baffle plate, and a low shear mixingzone positioned downstream from the high shear agitation zone betweenthe second end of the mixing chamber and the first baffle plate; and astatic mixer positioned at the second end of the mixing chamber, whereinthe low shear mixing zone is completely free of a mechanical mixingdevice.

Clause 2: The chemical treatment apparatus of clause 1, furthercomprising a mechanical mixing device connected to the first end of themixing chamber and extending into the high shear mixing zone.

Clause 3: The chemical treatment apparatus of clause 2 or 3, wherein themechanical mixing device comprises a motor and an impeller.

Clause 4: The chemical treatment apparatus of any of clauses 1-3,wherein the impeller is positioned within the high shear mixing zone.

Clause 5: The chemical treatment apparatus of any of clauses 1-4,wherein the motor is directly connected to the impeller.

Clause 6: The chemical treatment apparatus of any of clauses 1-5,wherein the first baffle plate comprises a plurality of pathways.

Clause 7: The chemical treatment apparatus of any of clauses 1-6,wherein the mixing chamber further comprises a second baffle platepositioned between the first baffle plate and the second end of themixing chamber.

Clause 8: The chemical treatment apparatus of any of clauses 1-7,further comprising a post-dilution zone positioned between the secondend of the mixing chamber and the static mixer.

Clause 9: The chemical treatment apparatus of any of clauses 1-8,wherein the length of the static mixer is greater than 5 inches.

Clause 10: The chemical treatment apparatus of any of clauses 1-9,wherein the mixing chamber has a volume of greater than or equal to ahalf gallon.

Clause 11: A method of diluting and activating a polymeric material, themethod comprising: (a) transporting a polymeric material and water intoa mixing chamber comprising a first end, a second end, a first baffleplate positioned between the first end and second end, a high shearmixing zone positioned between the first end of the mixing chamber andthe first baffle plate, and a low shear mixing zone positioneddownstream from the high shear mixing zone between the second end of themixing chamber and the first baffle plate; and (b) mixing the polymericmaterial and water in the high shear mixing zone, wherein the low shearmixing zone is completely free of a mechanical mixing device.

Clause 12: The method of clause 11, wherein the mixing of step (b)comprises mixing the polymeric material and water in the high shearmixing zone with a mechanical mixing device.

Clause 13: The method of clauses 11 or 12, further comprisingpost-diluting the mixed polymeric material and water in a post-dilutionzone, and mixing the post-diluted mixture of polymeric material andwater in a static mixer.

Clause 14: The method of any of clauses 11-13, wherein the post-dilutedmixture has a polymeric material concentration of 0.25% to 1%.

Clause 15: The method according to any of clauses 12 to 14, wherein themechanical mixing device comprises an impeller and a motor.

Clause 16: The method of any of clauses 11-15, wherein the impeller ispositioned within the high shear mixing zone.

Clause 17: The method of any of clauses 11-16, wherein the motor isdirectly connected to the impeller.

Clause 18: The method of any of clauses 11-17, wherein the length of thestatic mixer is greater than 5 inches.

Clause 19: The method of any of clauses 11-18, wherein the mixingchamber has a volume of greater than or equal to a half gallon.

Clause 20: The method of any of clauses 11-19, wherein the first baffleplate comprises a plurality of pathways.

Clause 21: The method of any of clauses 11-20, wherein the mixingchamber further comprises a second baffle plate positioned between thefirst baffle plate and the second end of the mixing chamber.

Clause 22: A system for diluting and activating a polymeric material,comprising: (a) chemical treatment apparatus for diluting and activatinga polymeric material comprising: (i) a mixing chamber comprising a firstend, a second end, a first baffle plate positioned between the first endand second end, a high shear mixing zone positioned between the firstend of the mixing chamber and the first baffle plate, and, a low shearmixing zone positioned downstream from the high shear mixing zonebetween the second end of the mixing chamber and the first baffle plate;and (ii) a static mixer positioned at the second end of the mixingchamber, wherein the low shear mixing zone is completely free of amechanical mixing device; (b) a water distribution apparatus in fluidcommunication with the chemical treatment apparatus; and (c) a polymerdistribution apparatus in fluid communication with the chemicaltreatment apparatus.

Clause 23: The system of clause 22, wherein the chemical treatmentapparatus, water distribution apparatus, and/or polymer distributionapparatus are operated with a controller.

Clause 24: The system of clauses 22 or 23, further comprising amechanical mixing device connected to the first end of the mixingchamber and extending into the high shear mixing zone.

Whereas particular embodiments and aspects of this invention have beendescribed above for purposes of illustration, it will be evident tothose skilled in the art that numerous variations of the details of thepresent invention may be made without departing from the invention asdefined in the appended claims.

The invention claimed is:
 1. A chemical treatment apparatus for dilutingand activating a polymeric material comprising: a mixing chambercomprising a first end, a second end, a first baffle plate positionedbetween the first end and second end, a high shear mixing zonepositioned between the first end of the mixing chamber and the firstbaffle plate, and a low shear mixing zone positioned downstream from thehigh shear agitation zone between the second end of the mixing chamberand the first baffle plate; and a static mixer positioned at the secondend of the mixing chamber, wherein the low shear mixing zone iscompletely free of a mechanical mixing device.
 2. The chemical treatmentapparatus of claim 1, further comprising a mechanical mixing deviceconnected to the first end of the mixing chamber and extending into thehigh shear mixing zone.
 3. The chemical treatment apparatus of claim 2,wherein the mechanical mixing device comprises a motor and an impeller.4. The chemical treatment apparatus of claim 3, wherein the impeller ispositioned within the high shear mixing zone.
 5. The chemical treatmentapparatus of claim 3, wherein the motor is directly connected to theimpeller.
 6. The chemical treatment apparatus of claim 1, wherein thefirst baffle plate comprises a plurality of pathways.
 7. The chemicaltreatment apparatus of claim 1, wherein the mixing chamber furthercomprises a second baffle plate positioned between the first baffleplate and the second end of the mixing chamber.
 8. The chemicaltreatment apparatus of claim 1, further comprising a post-dilution zonepositioned between the second end of the mixing chamber and the staticmixer.
 9. The chemical treatment apparatus of claim 1, wherein thelength of the static mixer is greater than 5 inches.
 10. The chemicaltreatment apparatus of claim 1, wherein the mixing chamber has a volumeof greater than or equal to a half gallon.
 11. A method of diluting andactivating a polymeric material, the method comprising: a) transportinga polymeric material and water into a mixing chamber comprising a firstend, a second end, a first baffle plate positioned between the first endand second end, a high shear mixing zone positioned between the firstend of the mixing chamber and the first baffle plate, and a low shearmixing zone positioned downstream from the high shear mixing zonebetween the second end of the mixing chamber and the first baffle plate;and b) mixing the polymeric material and water in the high shear mixingzone, wherein the low shear mixing zone is completely free of amechanical mixing device.
 12. The method according to claim 11, whereinthe mixing of step b) comprises mixing the polymeric material and waterin the high shear mixing zone with a mechanical mixing device.
 13. Themethod of claim 11, further comprising post-diluting the mixed polymericmaterial and water in a post-dilution zone, and mixing the post-dilutedmixture of polymeric material and water in a static mixer.
 14. Themethod of claim 13, wherein the post-diluted mixture has a polymericmaterial concentration of 0.25% to 1%.
 15. The method of claim 12,wherein the mechanical mixing device comprises an impeller and a motor.16. The method of claim 15, wherein the impeller is positioned withinthe high shear mixing zone.
 17. The method of claim 16, wherein themotor is directly connected to the impeller.
 18. The method of claim 13,wherein the length of the static mixer is greater than 5 inches.
 19. Themethod of claim 11, wherein the mixing chamber has a volume of greaterthan or equal to a half gallon.
 20. The method of claim 11, wherein thefirst baffle plate comprises a plurality of pathways.
 21. The method ofclaim 11, wherein the mixing chamber further comprises a second baffleplate positioned between the first baffle plate and the second end ofthe mixing chamber.
 22. A system for diluting and activating a polymericmaterial comprising: a) a chemical treatment apparatus for diluting andactivating a polymeric material comprising: i) a mixing chambercomprising a first end, a second end, a first baffle plate positionedbetween the first end and second end, a high shear mixing zonepositioned between the first end of the mixing chamber and the firstbaffle plate, and a low shear mixing zone positioned downstream from thehigh shear mixing zone between the second end of the mixing chamber andthe first baffle plate; and ii) a static mixer positioned at the secondend of the mixing chamber, wherein the low shear mixing zone iscompletely free of a mechanical mixing device; b) a water distributionapparatus in fluid communication with the chemical treatment apparatus;and c) a polymer distribution apparatus in fluid communication with thechemical treatment apparatus.
 23. The system of claim 22, wherein thechemical treatment apparatus, water distribution apparatus, and/orpolymer distribution apparatus are operated with a controller.
 24. Thesystem of claim 22, further comprising a mechanical mixing deviceconnected to the first end of the mixing chamber and extending into thehigh shear mixing zone.